pub struct Demo {
    pub x: i32,
    y: i32,
}

//@ set x = "$.index[*][?(@.name=='x')].id"
//@ is "$.index[*][?(@.name=='Demo')].inner.struct.kind.plain.fields[0]" $x
//@ count "$.index[*][?(@.name=='Demo')].inner.struct.kind.plain.fields[*]" 1
//@ is "$.index[*][?(@.name=='Demo')].inner.struct.kind.plain.fields_stripped" true
